JPH0683597B2 - Reluctance generator controller - Google Patents

Description

TECHNICAL FIELD The present invention relates to a reluctance generator control device.

(Prior Art) A reluctance generator, which is a kind of synchronous generator, is being evaluated for its performance in a transportation system or the like, which requires a power generation system with high output and small size and light weight.

Reluctance generators have been known for a long time and are well known.

This reluctance generator is described, for example, in Japanese Patent Laid-Open No. 61-73596.

FIG. 3 is a block diagram of an example of a control device for controlling a three-phase reluctance generator described in Japanese Patent Laid-Open No. 61-73596. Next, the control of the three-phase reluctance generator will be described with reference to this block diagram. In the figure,
The reluctance generator 4 is connected to the prime mover 1 via the coupling device 2.
And is rotated by the driving force of the prime mover 1.
The output of the reluctance generator 4 is converted into direct current by, for example, a 6-step voltage source inverter 5, smoothed by a smoothing capacitor 6, and supplied to a load 8 having a resistance value Rl.
Reference numeral 7 denotes a starting circuit, which operates until the reluctance generator 4 is in a steady state and gives initial excitation. The position detector 3 is attached to the rotary shaft of the reluctance generator 4, and the detected position signal is subjected to predetermined signal processing by the rotor position detection circuit 11, and the position detection signal is the position detection signal of the reluctance generator 4. The exciting current (direct current) is sent to the Id detector 51, and the rotation speed detection value is sent to the base drive circuit 13 of the voltage source inverter 5. Direct axis current Id of reluctance generator 4
Is detected by the current transformer 50 provided on the output lead wire, and is input to the subtractor 52 together with the direct-axis current command value. The output signal of the subtracter 52 is subjected to a predetermined process by the error amplification compensation circuit 53 and sent to the base drive circuit 13, where the voltage source inverter 5
To control. At this time, the phase angle of the inverter, that is, the load angle δ of the reluctance generator 4 is controlled by the feedback as shown so that the actual direct-axis current Id of the reluctance generator 4 follows the command value of the direct-axis current Id. Controlled by the system. Here, the DC voltage Vdc supplied to the load 8 having the resistance value R1 is
DC voltage command value generation circuit 10 so that constant voltage characteristics can be obtained
Of the DC voltage detector 9 for variable control. Therefore, the DC voltage detector 9 detects the DC voltage supplied to the load and inputs it to the subtractor 54 to compare it with the command voltage. Forming a loop.

(Problems to be Solved by the Invention) As described above, the conventional reluctance generator control device causes the output voltage of the reluctance generator to follow the DC voltage command value and stabilizes the output voltage. A control device 12 'shown by a dotted line in the drawing is provided. The controller 12 'is provided with a feedback system for direct-axis current control and a feedback system for controlling DC voltage supplied to the load as described above, and the direct-axis current Id of the reluctance generator 4 is supplied to the DC voltage. The load angle δ is changed so as to follow the command value, and control is performed by the DC voltage control loop so that a constant voltage is supplied to the load 8. For this reason,
The conventional reluctance generator control device has a problem that the configuration is complicated and the cost is high. Therefore, the present invention solves the problems of the prior art and provides a reluctance generator control device having a simple structure.

(Means for Solving the Problems) In order to solve the above-mentioned conventional drawbacks, the present invention is directed to a reluctance generator driven by a prime mover and a direct current from a voltage source inverter connected to the output side of the reluctance generator. , A DC voltage detector for detecting the DC voltage supplied to the load, a rotor position detector mounted on the shaft of the reluctance generator, a DC voltage command value and the DC voltage detector A reluctance generator control device comprising a control device to which an output signal is input, and an inverter drive circuit to which the output signal of the control device and the rotor position detection signal are input, a direct current voltage command value and a direct current voltage detector The rotation signal of the reluctance generator is calculated from the drive phase angle of the voltage source inverter and the rotation signal of the reluctance generator calculated by the inverse trigonometric function value of the output signal ratio of the The present invention provides a reluctance generator control device having control means for generating a drive signal of a voltage source inverter corresponding to the above.

(Operation) Since the present invention controls the load angle of the reluctance generator as a function of the voltage command value of the DC load, the conventional control system for the exciting current (direct-axis current) of the generator becomes unnecessary, and the control is possible. The device can be easily constructed.

Example An example of the present invention will be described below with reference to the drawings.

The present invention controls a reluctance generator according to the following principle. That is, the instantaneous electric power P connected to the load side of the reluctance generator 4 when power is supplied to the load 8 having the resistance value Rl via the 6-step voltage source inverter 5 as shown in FIG. (1/3) × {(1 / xq) − (1 / xd)} × sin2δ (Vdc) ²
= (((Vdc) ² / R1} + CVdc (dVdc / dt)) (1) Expression (1) is the output voltage if the operation amount of the reluctance generator 4 is only the load angle δ. , That is,
It shows that the DC voltage Vdc can be used as the controlled variable. By the way, when the load resistance R1 is fixed, the DC voltage Vdc and the load angle δ do not correspond one-to-one due to the influence of the saturation characteristics of the direct-axis reluctance xd and the horizontal-axis reluctance xq. The linear compensation cannot control the stable direct current.

However, in this type of reluctance generator, it has been found that the change range of the load angle δ is small even if the DC voltage Vdc changes, and in the formula (1), {(1 /
xq)-(1 / xd)} can be regarded as a constant. Therefore, in equation (1), since the non-linear element is only sin2δ, the command value of the load angle δ is expressed by the function of the DC voltage Vdc δ = (1/2) sin ⁻¹ [K {1- (Vdc / Vdc *) }]…
(2) However, if given as Vdc *: DC voltage command value, equation (1) becomes a linear differential equation with respect to Vdc. Solving equation (2), Vdc = [{(B / A) + 1 / Vdc ₁ } exp (At)-(B / A)] ^-1 … (3) where (t = 0: Vdc ₁ ) Here, A = (− 1 / c) × [(1/3) × {(1 / xq) − (1 / xd)} ×
K− (1 / R1)] (4) B = (1 / 3c) × {(1 / xq) − (1 / xq)} × (K / Vdc *)
(5) Therefore, when A is negative, it converges to a constant value at t → ∞, and at this time, the value of Vdc becomes equal to the steady value obtained by the equation (1).

FIG. 2 is a characteristic diagram showing the relationship between the DC voltage Vdc and the load angle δ. In the above formulas (1) to (5), the voltage command value
When Vdc * and load resistance R1 are given, the δ command value moves along the function curve of (a), (b), etc. as the voltage increases, and the constant R curve (a), (b) is the equilibrium point. Settle at the intersection with (c). Considering the case where ΔVdc changes from the equilibrium point Vdc ₀ , (dVdc / dt) = (− 1 / 3c) × {(1 / xq) − (1 / xd)} ×
(K / Vdc *) × Vdc ₀ × ΔVdc (6), which changes to return to the equilibrium point even if fluctuations occur.
Here, it is understood that when the coefficient K is increased, the DC output voltage with respect to the load resistance variation can be decreased, and the DC output voltage can be adjusted by the voltage command value Vdc *.

FIG. 1 is a block diagram of a reluctance generator control device of the present invention. In the figure, the same components as those of the conventional example of FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted. In the present invention, the control device comprises a divider a, a subtractor b, a multiplier c, and an inverse sine wave generator d. The divider a divides the DC voltage command value Vdc * and the DC voltage Vdc supplied to the load, and the subtractor b, the multiplier c, and the inverse trigonometric function generator d calculate the load angle calculated by the equation (2). Determine δ and send a control signal to the base drive circuit 13. The base drive circuit 13 controls the voltage source inverter based on the input control signal and adjusts the DC voltage Vdc.

In the above formula (3) which determines the stable operation of the reluctance generator control device according to the present invention, A is represented by the formula (4), which is also the time constant of the change of Vdc and has a negative absolute value. The larger the value, the better the responsiveness. Further, K that determines the value of A also determines the slopes of the curves (a) and (b) shown in FIG. That is, as can be seen from FIG. 2, the magnitude of the voltage fluctuation when the load 8 changes varies.

(Effects of the Invention) As described above, the reluctance generator control device of the present invention does not require a direct-axis current control loop and has only a DC voltage feedback system, so the control device is simplified. it can. Further, since the multiplication circuit and the inverse trigonometric function generator of the control device can be realized by a single IC circuit, the control device can be constructed at low cost.

[Brief description of drawings]

FIG. 1 is a block diagram of the present invention, FIG. 2 is an explanatory diagram, and FIG. 3 is a block diagram of a conventional example. DESCRIPTION OF SYMBOLS 1 ... A prime mover, 4 ... Reluctance generator, 5 ... Voltage source inverter, 8 ... Load, 9 ... DC voltage detector, 10 ... DC voltage command value generation circuit, 12 ... Control device, 13 ... Base drive circuit.

Claims (1)

[Claims] 1. A reluctance generator driven by a prime mover, a load to which direct current is supplied from a voltage source inverter connected to the output side of the reluctance generator, and a DC voltage for detecting the DC voltage supplied to the load. A detector, a rotor position detector mounted on the shaft of the reluctance generator, a controller to which a DC voltage command value and an output signal of the DC voltage detector are input, an output signal of the controller and the rotor. In a reluctance generator control device equipped with an inverter drive circuit to which a position detection signal is input, the drive phase angle of the voltage source inverter calculated by the inverse trigonometric function value of the ratio of the DC voltage command value and the output signal of the DC voltage detector. And a control means for generating a drive signal of the voltage source inverter corresponding to the rotation signal of the reluctance generator from the rotation signal of the reluctance generator. And a reluctance generator control device.